IndentPrintWriter.java

package org.freehep.util.io;

import java.io.PrintWriter;
import java.io.Writer;

/**
 * A PrintWriter that keeps track of an indentation level and indents the output
 * appropriately.
 * 
 * @author Tony Johnson
 * @author Mark Donszelmann
 * @version $Id: IndentPrintWriter.java,v 1.3 2008-05-04 12:22:13 murkle Exp $
 */
public class IndentPrintWriter extends PrintWriter {
	/**
	 * Creates an Indent PrintWriter.
	 * 
	 * @param w
	 *            writer to write to
	 * @param level
	 *            starting indentation level
	 */
	public IndentPrintWriter(Writer w, int level) {
		super(w);
		setIndent(level);
	}

	/**
	 * Creates an Indent PrintWriter with indentation level 0.
	 * 
	 * @param w
	 *            writer to write to
	 */
	public IndentPrintWriter(Writer w) {
		this(w, 0);
	}

	@Override
	public void print(boolean s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(char s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(char[] s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(double s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(float s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(int s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(long s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(Object s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void print(String s) {
		doIndent();
		super.print(s);
	}

	@Override
	public void println() {
		indented = false;
		super.println();
	}

	// all other println's are implemented by the superclass in terms of print's

	private void doIndent() {
		if (indented) {
			return;
		}
		indented = true;
		for (int i = 0; i < indent; i++) {
			super.print(indentString);
		}
	}

	/**
	 * Increase the indentation
	 */
	public void indent() {
		indent++;
	}

	/**
	 * Decrease the indentation
	 */
	public void outdent() {
		indent--;
	}

	/**
	 * Return the current indent count
	 * 
	 * @return current indentation level
	 */
	public int getIndent() {
		return indent;
	}

	/**
	 * Set the current indent count
	 * 
	 * @param level
	 *            new level
	 */
	public void setIndent(int level) {
		indent = level;
	}

	/**
	 * Return the current indentString
	 * 
	 * @return indent string
	 * 
	 * @see #setIndentString(String)
	 */
	public String getIndentString() {
		return indentString;
	}

	/**
	 * Set the current indentString. Default is a single tab per indent level.
	 * 
	 * @param indentString
	 *            The characters to prefix each line with (repeated for each
	 *            indent level)
	 */
	public void setIndentString(String indentString) {
		this.indentString = indentString;
	}

	private int indent = 0;

	private boolean indented = false;

	private String indentString = "  ";

}